The present invention relates to a system for recognizing three dimensional objects, and more particularly a system which is useful, for example, as the eyes of robots and which is adapted for recognizing the position, shape, size, etc. of a three-dimensional object.
Two image pickup means, for example, TV cameras are necessary for three-dimensionally recognizing three-dimensional objects. Using a multiplicity of points on the images on the two TV cameras, if it is possible to identify two points (one on each of the images) corresponding to a specific point on the object, the position coordinates of these corresponding points on the images and the relationship involved in the arrangement of the TV cameras provide dayta as to the position of the specific point on the object in a three-dimensional space.
However, it is extremely difficult to identify one point on one image corresponding to one point on the other image. It is conventional practice to set a small area, termed a "window" on one image and search on the other image for a brightness distribution similar to the brightness distribution of the small area. This method requires a large number of a repetitions of brightness distribution pattern comparing process and therefore a prolonged period of time for processing and involves the likelihood that it is impossible to establish two points of proper correspondence, whereby the method may fail to recognize the object correctly.